Equipment for automatically controlling single phase motors



Dec. 29, 1953 HEIDMANN 2,664,536

EQUIPMENT FOR AUTOMATICALLY CONTROLLING SINGLE PHASE MOTORS Filed Feb. 17, 1953 I H l I l a m 2'2. E

H as $1 [5 F an 10d 111:

Patented Dec. 29, 1953 ,umreo STATES PATENT. corner.

2,664,536 EQEIEME EQ A ATI QL a new nli t nts" Claims priority, application France February 29,1952

1 The present invention relates to equipment for controlling.singleiphasemotors bymean a plurality of individual contactors of the electrornag rnetic or, electrcpneumatic type. The equipment in accordance with the invention is llfifiiul pan ticularly, but not exclusively, for controlling single phase traction motors by means of start; ing' contactors connected with the tappings of a regulating transformer.

-The .problem involved such a control sy s temis t'o close lfirstapredetermined group of con tactors connected with certain taps Of the transformer, .for example .with three or tour taps, for the purpose of establishing ,a first step the starting sequence, then .to .openthe first ccntactor of this group and vreplace it bya new contactor connectedwith another tap vof the transformer, and so on.

One of the iobjectsof the invention is to provide simple equipment for efiectingtheseoperations' with maximum guarantee of proper controlby means .of aimaster controller which per mits a completely automatic, or partially auto matic, start subordinated .to a single acceleration relay. V

Another objectiof the invention ,is to v prevent the simultaneous closing of contactors, which would result in short circuitsvor overloads.

' Accordingi-to the .presentinvention, equipment for controlling single phase vmotonsby l fiilsuq a master controllerand accelerationrelay and in dividual starting oontactors connected with -the respective taps of a regulating transformer is eharacterizedbywthe factthat the operatingpoil tor each individual .contactor is. connected in turnhwith threeenergizingwires, the first being a starting.wirerwhichienergizes the coilby ineans of auxiliary contacts which assure the p roper -order of .closing .of vthe contactors, the second (being a holding wire which energizes thesa me opl'erating coil by meansof auxiliaryrhQlq ll 0 1- 'tactsrandithe third being a wire iorppeningthe contactors, this opening wire being connected with the. coil through auxiliary transfer conta s and being also connected with the contacts pf Lthe accelerationrelay insucha way as to ground the openingwire when the accelerationrelay contacts are closed and thereby open the starting vvcontactors.

The natureand objects of ,the invention will :moreiully appear :fromthe following descriptionland claims in conjunctionwith the accompanyingdraWingswhich showa circuit diagramof iequipmentlembodyingi the invention.

In the drawing there i shown, rbyflway otex- 2 X2 an .the retu n tions or steps I Yfllhe'rna'ster "controller currentQ tosupply current to the various comm .re a ii je. In 'th'e'w re L L or l l "In the wire fife, there "is a normally ,clo sed auxiliary Contact Z f carr'ie'd by one of the aux liary co ac se ieetor meson err-e292 ample. an embod ment. t iny l h in twelve ndiv dua tar n s mes ers n a m tcro n r lc wit fo r operat n p s ion The ind vid a .c n a tor I o 12 e i icqnne t th are c onnected to the bus bars through r'nairi line eqntac ts L an L2 a arami cat n ie An acceleration relay A has contacts dl and pperatinrg coils cl b and cl. The con cl und ,of heavy wireand isconnected' in series ne ofthe motors M bm'g' hunt- .e by a resis la cer ha it is ne gizes a irec nne e wq jeu f 7 {lfhe mastercontroller K is illustrated in the q i fsrite h all and four 0 erat'ine'posiw irl nst awil new s sisitc t i nial n ih operatin t p -t m s e controller supplies current to" anioperating nin rel-t0 finish awn n b bf the erationrelay A and a starting wire' mn are connecte d in series. Ailiold'ing' wire mt and an opening wire 01) are connecteddiiectly to the operatjo'and a'voltageis' henfce' applied to '6 operating steps 'I' to IV. "The wire fo also s hes current tothe coils BL! and ifl hfe 'eoms ctars' )an'dVLZ' have auxiliary contacts ti and t2 whichare closed whe'n LI and g jvvire auxiliary contacts ing arranged in parallel with one an-- Th geratini coils BL! and BLr rithe actors}; I 'an ag'm are connected in" parjall el with, one anot'h'er and a e connected to the ,re o py twofparallelwir s mid and ma,"ther'fe is a norinally' open auxiliary 11 carried by one of'th'eli'ne c'ontacto'rs line .contact'or's L1 or L2 and a; normally'op'en rri d' by ,the individual l; and lg beingcon- =1? nected in series. This arrangement assures that the line contactors LI and L2 cannot close unless tne contactor l is closed first. As soon as the two line contactors LI and L2 are closed, the auxiliary contact L1 closes the upper holding wire ma while the contact Z2 open the lower closing wire 16. this keeps the line contactors LI and La closed alter the opening or the contactor l.

Each oi the moivioual contactors l to l2- whicn may be of the electromagnetic or electropneuhiatic typenaS an operating coil designated, respectively, Bl to BIZ and auxiliary or interlocking contacts which belong to six series. The interlocking contacts of tne series la to lzd are normally closed and are connected in series with one another in the starting wire mm. The interlocxing contacts or the series w to llb are normally open and are connected in branch lines leading Irom the starting wiremn to the operating cons B2 to B1: or the individual contactors 2 to l2. It will be seen that branch lines leading to the operating coils B2, B3 and B4 are connected with the starting wire mm between the master controller K and the rust of the normally closed auxiliary contacts al to (H2. The branch line leading to operating coil B5 is connected to the strarting wire mn between contacts la and 2a, the operating 0011 Be is connected to the starting wire mu between contacts 2a and 3a, etc. It will be Iurther noted that normally open auxiliary contact lb is in the branch line leading to operating 0011 B2, auxiliary contact at; is in the branch line leading to operating 0011 B3, etc. In

designating the operating cons and the auxiliary contacts, the numeral indicates in each instance the individual contactor l to l2 to which the operating coils and auxiliary contacts belong. The operating coil Bl is connected to the starting wire mn at a point beyond all or the series-connected normally closed auxiliary contacts la to lza. and in series with the normally closed contacts ti and $2 of the line contactors Ll and L2.

The arrangement described above assures the proper sequence of operation or the individual contactors to l2. The operating coil Bl of the contactor I cannot be energized by the starting wire mn unless all of the contacts of the rirst series la to I26. are closed, which means unless all or the contactors l to l2 are open. Moreover, the

auxiliary contacts ti and t2 or the line contactors u Ll and L2 must be closed, which means that these line contactors are open. Operating coil B2 of the contactor 2 can be energized to close the contactor only after auxiliary contact lB has been closed by the closing of contactor l. manner, each succeeding contactor can be closed only after the preceding contactor has been closed. Hence, proper starting conditions and proper sequence of operation of the contactors are assured.

The third and fourth series of auxiliary contacts provided on the contactors l to l2 are designated, respectively,,2c to Ho and Id to l ld. The auxiliary contacts 2c to He are normally closed and are connected in series, respectively, with the normally open auxiliary contacts lb to lilb in the branch lines leading from the starting wire mn to the operating coils B2 to El l. The auxiliary contacts ld to lld are normally open and are in branch lines leading from the holding wire mt to the operating coils Bl to Bll. The auxiliary contacts to He and Id to lld provide for holomg the contactors l to ll closed and may hence be designated as holding contacts. As described above, current for initially energizing In like 7 ing operating 60118 the operating coils Bl to Bl2 of the individual contactors l to I2 is supplied by the starting wire mn. l'his current also nows through the arming coil bl or the acceleration relay A which is thereby energized to close this relay. However, this initial energization is soon interrupted and replaced by the holding energization provided by current supplied from the holding wire mt through the holding contacts ld to lld and the corresponding auxiliary contacts of the series e and i described below. So that the transition from starting to holding is ertected without mterruption or current in the coils Bl to BIZ, an overlap is provided in the operation of the series 0 and series d contacts, so that the series d contacts close before corresponding 0 series contacts open.

The nith and sixth series of auxiliary contacts with which the individual contactors l to l2 are provided are transfer contacts and are designated as series e and series I, respectively. Auxiliary contacts of to HI are connected iii series with the holding contacts ld to 801, respectively, in the branch lines connecting the operating coils Bl to B8 with the holding wire mt and arenormally closed. Auxiliary contacts dc to He are normally open and are in branch lines connect- Bl to B8 with the opening wire 01), the auxiliary contacts ie to He being also connected in series with the holding contacts ld to 8d. It will be noted that auxiliary contacts ie and 4 of individual contactor l are connected in circuit with the operating coil Bl of contactor i, auxiliary contacts 5e and 5) or contactor 5 are connected in the circuit of the operating coil B2 or contactor 2, etc. The auxiliary contacts of series 2 and transfer the control of the operating coils from the holding wire mt to the opening wire 01). Thus, for example, when contactor 4 is open and contactor l is closed, the operating coil Bl of contactor l is energized by current supplied from the holding wire mt through contacts 4] and Id. If contactor 4 is now closed, auxiliary contact 41 will be opened while auxiliary contact fie will be closed, so that the operating coil Bl is now connected through contacts id and ie with the opening wire on. By being transferred from connections with the holding wir mt to connections with the opening wire 01), the operating coils of the contactors are put under the control of the acceleration relay A, as will be explained below. An overlap is provided in the operation of the series e and series auxiliary contacts, so that series e contacts will be closed before series 1 contacts are opened, to avoid interruption in th current supplied to the operating coils of the contactors.

In addition to the connections described above, there are three control wires fl, f2 and f3 leading from the master controller K. The first control wire fl is connected through the holding contact ld with the operating coil Bl of the contactor l. The second control wire i2 is connected in similar manner to the operating coil B4 and the third control wire i3 is connected to the operating coil B1. In its first step of operation I, the master controller K supplies current to all of the control wires fl, f2 and f3. In the second step 11 of the master controller, the control wire fl is deenergized. In the third step III, the control wire f2 is de-energized and in the fourth step IV, the control wire i3 is de-energized. The function and purpose or the control wires fl, f2 and )3 will be described more lll.iy below.

With the circuits shown and described, the individual contactors I to I2 are closed and opened in such a way that in each step of the operation, with the exception of the first, a group oi four contactors are closed, the remaining contactors being open. As additional contactors are succcssively closed in sequence, a corresponding number of previously closed contactors are opened, so that thenumber of contactors closed at any onetime is four.

Starting'with the line contactors L! and L2 and'all of the individual contactors I to !2 open, and with the acceleration relay A de-energize movement of the main controller K to any of the four positions I to IV applies voltage to the operating wire fo and, through it, to the coil bi of the acceleration relay A and to the starting wire mn. As the auxiliary contacts In to P20. and the axiliary contacts t! and t2 are all closed, the operating coilBIoi the contactor I is energized to close this contactor. This results in closing theholding contact Id, so that the contactor l is kept closed, and also closing the auxiliary contacts Ig in the line fc; so as to energize the oper ating coils BLI and BL? to close line contactors LI and L2. The line contactors Li and L2 are then held closed by current supplied through. the holding contact Z! in line ma. The closing of contactor I also closes auxiliary contact ID in the branch line leading from the starting wire mm to the operating coil B2 of the cont-actor 2, so that the latter contactor is closed and is held closed by the holding contact Zd. In like manner, contact'ors 3 and '4 are successively closed.

' The closing or" the contac'tor '4 closes the auxiliary contacts 46 and opens contacts of, so that the holding circuit of the operating coil Bi of the first contactor I is transferred from the holdin wire mt to the opening wire 02). During this operation, the currents in the wires co and mi are limited and balanced by means of control resistances rI, r2 and 13. The. acceleration relay A, which was initially opened by current flowing through the operating wire fo, the coil DI and :starting wire mn, is lcept open by a fraction of the. motor current flowing through the coil c! which,as described above, is in the return line iromth'e motors and is shunted by a resistance r. As the motors accelerate, the starting current is progressively reduced. When a predetermined reduction in the motor-starting current has cccurred, the acceleration relay A drops and, by its contacts dl, ground the opening wire 01;. Consequently, the operating coil Bl, which was energized by the opening wire co, is de-energized, so that the contactor I opens and its auxiliary "contact Ia closes. As auxiliary contacts 4b are already closed, current is now supplied through thaw-ire fo, coil bl, starting wire mm and contactshla, 4b and 50 to the operating coil B5, to close contactor 5. This contactor is then held closed by its holding contact 5d. The closing of contactor'fi closes contacts 5e and opens contacts 5], so that the control of operating coil B2 is transferred from the holding wire mt to the opening wire 0v. Hence, the next time the acc'eler'ation relay drops-upon predetermined decrease of the motor-starting current-contactor "2 will be ole-energized and contactor 6 will be energized. The successive operation of the other contactors occurs in like manner. Thus, contactor 3 opens when contactor i closes, contactor '4' opens when contactor 8 closes, etc. Thus, at any one time, there is a group of four .con'tactors closed.

During the closing of each contacton-a short '75 current impulse passes through the wire 'mn' and the coil bI of the acceleration relay A and lifts the armature of the relay to open the contacts dI. Thereafter, the relay is held by the starting current which flows through the lower coil cI untildueto acceleration of the motors-the starting current decreases to a. predetermined. point, whereupon the acceleration relay A dropsand initiates a new step of the startingoperation, as described above.

It will'be seen that the starting of themotors M proceeds automatically, being controlled by the acceleration relay A. However, the point to which the starting operation proceeds :depends on the position of the mastercontroller Kr With the. master controller at. step'I, current supplied through the wire fl keeps the'contactor .I from dropping by continuing to energize the operating coil BI, even though the supply of current-from the opening wire or is interrupted by thezdropping of the acceleration relay and the resulting grounding of the wire 01). Since contactor. I is kept closed, the auxiliary contacts Ia remain open and hence current cannot be supplied from the starting wire mn to the next contactor 5. Thus, with the master controller set at step I, the starting operation cannot proceed beyond the closing of the first group of contactors I to 4. With the master controller K set at step II, the control wire f2 supplies current to the operating coil B4 to keep the contactor 4 from opening. The progress of the starting operation is thereby halted at a stage in which contactors 4, 5, .5 and l are closed. In like manner, with the master controller K set at step III, the control wire f3 keeps the contactor'l from opening, so that the progress of the starting operation is haltedat a stage in which contactors Ti, 8, 9 and I U are closed. This has th result that, in the starting operation, the equipment does not go beyond the steps corresponding to the positions of the handle on the master controller. If the handle is set for the last step, the starting operation will proceed uninterrupted.

The coil aI of the acceleration relay A is connected by a wire 3 to the contact f'i through which current is supplied from the operating wire f0. -This contact is operated manually, for example by downward movement on the pivoted handle H of the master controller K. Ir", during the progress of the automatic start, the handle 'His pressed downwardly to close the contact f'i, the upper coil-a1 of the acceleration relay is energized, so that the armature of the relay is held up and the progress of the starting operation is interrupted.

It will be undersmod that the system shown and described represents only one example of embodiment of the invention and that many modifications can be made within the scope .of the present invention as defined by the appended claims.

What I claim and desire to secure by Letters Patent is:

'1. In equipment for automatically controlling single phase motors, a regulating transformer with a plurality of taps, a plurality of individual con'tactors each having an operating coil, main contacts and auxiliary contacts comprising interlocking contacts, holding contacts and transfer contacts, connections between the main contacts of the contactors and said taps respectively and connections between the main contacts of the contactors and said motors so that the closing of said main contacts connects 'said motors with the respective taps of said transformer, an acceleration relay having cooperating contacts, a master controller, and connections between the aforesaid elements comprising three wires connected with and excited by the master controller in all positions of said controller, the first of said wires being a starting wire which is connected with the operating coils of said contactors through said interlocking contacts which are connected in series to assure a predetermined order of closing of said contactors, the second of said wires being a holding wire which is connected to the operating coil of each contactor through the holding contacts of the respective contactor so as to hold the contactor closed after it has been closed by the starting wire, and the third of said wires being an opening wire which is connected on one hand with the operating coils through the respective transfer contacts and on the other hand with one of said contacts of the acceleration relay, the other of said cooperating contacts being connected with ground to ground said opening wire when the cooperating contacts of the acceleration relay are closed.

2. In equipment for automatically controlling single phase motors, a regulating transformer having a plurality of taps, a plurality of contactors each having an operating coil, main contacts and auxiliary contacts comprising interlocking contacts, holding contacts and transfer contacts, an acceleration relay having cooperating contacts, a master controller, and connections between the aforesaid elements comprising connections between the main contacts of the contactors and said taps respectively and connections between the main contacts and said motors so that the closing of said main contacts connects the motor with the respective taps of the transformer, and three wires connected with and excited by the master controller in all positions of said controller, the first of said wires being a starting wire which is connected with the operating coils of the contactors through said interlocking contacts which assure the closing of the contactors in predetermined order, said interlocking contacts comprising normally closed contacts connected in series with one another and normally open contacts connected in parallel with one another and interposed between the starting wire and the operating coils of the respective contactors, the second of said wires being a holding wire which is connected to the operating coil of each contactor through the holding contacts of the respective contactor so as to hold the contactor closed after it has been closed by the starting Wire, and the third of said wires being an opening wire which is connected on one hand with the operating coils through the respective transfer contacts and on the other handwith one of said contacts of the acceleration relay, the other of said cooperating contacts being connected with ground to ground said opening wire when the cooperating contacts of the acceleration relay are closed.

3. Equipment according to claim 1, in which said holding contacts comprise normally closed contacts interposed between the starting wire and the operating coils of the individual contactors and normally open contacts interposed between said coils and the holding wire, ,said contacts being spaced to provide an overlap between the opening of the normally closed con- L,- tacts and the closing of the normally open contacts.

4. Equipment according to claim 1, in which said transfer contacts comprise normally open contacts interposed between said operating coils of the individual contactors and said opening wire and normally closed contacts interposed between said coils and said holding wire, said contacts being spaced to provide anoverlap between the opening of said normally closed contacts and the closing of said normally open contacts.

5. In eqnuipment for automatically controlling single phase motors, a regulating transformer having a plurality of taps, a plurality of individual contactors each having an operating coil, main contacts and auxiliary contacts comprising interlocking contacts, holding contacts and transfer contacts, an acceleration relay having cooperating contacts, a master controller having a handle and a contact operable by said handle, and connections between the aforesaid elements comprising connections between the main contacts of said contactors and said taps respectively and connections between said main contacts and said motors so that the closing of said main contacts connects the motors with the respective taps of the transformer, and three wires connected with and excited by the master controller in all positions of said controller, the first of said wires being a starting wire which is connected to the operating coils of said contactors through said interlocking contacts which are connected in series with one another to assure a predetermined order of closing of said contactors, the second of said wires being a holding wire which is connected to the operating coils of said contactors through the holding contacts of the respective contactors so as to hold the contactor closed after it has been closed by the starting wire, and the third of said wires being an opening wire which is connected on one hand with the operating coils of the respective contactors through said transfer contacts and on the other hand with one of the contacts of said acceleration relay, the other of said contacts of the acceleration relay being connected to ground to ground said opening wire when the acceleration relay is closed, said acceleration relay havmg an operating coil connected in series with the motors and shunted by a resistance, an armmg coil connected with said starting wire and a coil for interrupting the starting sequence, said interrupting coil being connected with said contact operable by the master controller handle.

6. In equipment for automatically controlling single phase motors, a regulating transformer having a plurality of taps, a series of contactors each having an operating coil, main contacts and auxiliary contacts comprising interlocking contacts, holding contacts and transfer contacts, an acceleration relay having cooperating contacts, a master-controller, and connections between the aforesaid elements comprising connections between the main contacts of the contactors and sa d taps respectively and connections between said main contacts and said motors so that closmg of said main contacts connects the motors w th the respective taps of the transformer three wires connected with and excited by the master controller in all of its operative positions the nrst of said wires bein a starting i whfch is connected with the operating coil of each co ntact, except the first, through interlocking contacts of the preceding contactor of said series to assure a predetermined order of closing of said contactors, the second of said wires being a holding wire which is connected to the operating coils of said contactors through said holding contacts of the respective contactors to hold said contactors closed when they have been closed by said starting wire, and the third of said wires bein an opening wire which is connected with operating coils of said contactors through transfer contacts of contactors which form a selected group depending upon the position of the master controller, said opening wire being connected to the contacts of said acceleration relay so as to be temporarily de-energized upon operation of said relay whereby a contactor earlier in said group is opened and a contactor later in the series is closed.

'7. Equipment according to claim 6, in which control wires are connected to the operating coils of selected contactors and to said master controller, said control wires being selectively energized by the master controller in the respective operating positions of said controller to keep energized the coils of contactors to which energized control wires are connected and thereby interrupt the progress of a motor-starting operation by overriding the action of said opening wire and keeping said contactors from opening.

8. In equipment for automatically controlling single phase motors, a regulating transformer having a plurality of taps, a series of individual contactors each having an operating coil, main contacts and auxiliary contacts, line contactors having contacts and operating coils, an acceleration relay, a master controller, connections between the main contacts of said individual contactors and said taps respectively, and connections from the main contacts of said individual contactors to the contacts of said line contactors and from the contacts of said line contactors to the motors so that closing of the line contactors and of selected ones of said individual contactors connects the motors with the respective taps, connections from the master controller and the acceleration relay to the operating coils of said individual contactors to energize said contactor coils successively in predetermined sequence, and to de-energize successively coils of individual contactors earlier in the series so that a predetermined number of coils is energized at a time, connections from said master controller to the operating coil of said contactor through auxiliary contacts of the first individual contactor in said series to energize said last mentioned coil to close said line contactor only when said first individual contactor is closed, and connections from said master controller to the operating coil of said line contactor through auxiliary contacts of said line contactor to maintain said line contactor closed after said first individual contactor has been opened.

9. In equipment for automatically controlling single phase motors, a regulating transformer having a plurality of taps, a series of contactors each having an operating coil, main contacts and auxiliary contacts, an acceleration relay having contacts, a master controller and connections between the aforesaid elements comprising connections between the main contacts of the contactors and the respective taps of the transformer and connections between said main contacts and said motors so that closing of selected ones of said individual contactors connects the motors with the respective taps of the transformer, three wires connected with and energized by said master controller, said wires being connected with the operating coils of said contactors through auxiliary contacts of said contactors and comprising a starting wire, a holding wire and an opening wire, said auxiliary contacts comprising interlocking contacts for connecting operating coils of said contactors with said starting wire to energize said coils, the operating coil of each contactor, other than the first, being connected with the starting wire through interlocking contacts of the next preceding contactor in the series to assure predetermined order of closing of the contactors, holding contacts for connecting said operating coils with the holdin wire after the contactors have been closed and transfer contacts for transferring said operating coils from connection with the holding wire to connection with the opening wire, the operating coil of each contactor, other than a selected number of contactors at the end of the series, being connected with the transfer contacts of a contactor which is a selected number of positions later in said series, said opening wire being connected to the contacts of said acceleration relay so as to be temporarily deenergized upon operation of said relay to de-energize the operating coil of any contactor connected to said opening wire by said transfer contacts, so that as successive contactors are energized, a corresponding number of contactors earlier in the series are de-energized to maintain constant the number that are energized.

LEON HEIDMANN.

No references cited. 

